Historically, hierarchical data has been represented in a structured layout that helps in the understanding of parent-child relationships in the data. One approach has been to display the data in a top-down manner wherein children nodes are shown connected to their parent node with positions below the parent node. Another approach includes displaying the data in a left-right manner wherein children nodes are shown connected to their parent node with positions to the right of a parent node.
These approaches encounter multiple difficulties when the display is altered, such as when a user changes the focus of a node display. Several approaches encounter difficulty in illustrating parent-child relationship even from the initial display of the nodes. Such approaches remove the hierarchical relationship hints present in a structured hierarchical arrangement, thus making the layout more difficult to comprehend.
As an example, FIG. 1A provides a display 30 wherein a plurality of nodes is shown after a user has changed the focus of the display 30. Before the user changed the focus, the “Robert Hornsby” node 32 was the parent of the “Susie Smith” node 34, but as shown in FIG. 1A, that parent-child relationship information was removed when the user shifted focus. As another example, FIG. 1B provides a display 40 wherein a plurality of nodes is shown after a user has changed the focus of the display (to that of the dot 42). Originally, the “Harry Hines” node 48 was the parent of the “Alycia Allen” node 50. However, as shown in FIG. 1B, such parent-child relationship information was not visually retained when the user shifted focus. These illustrate but a few of the difficulties.